The invention relates to a viewer for the successive viewing of a number of transparent images, comprising a casing with a viewing aperture provided with a lens and a counter-aperture aligned therewith, which apertures are formed in two opposite faces of the casing, and further comprising a carrier which is detachably fitted in the casing and which supports a number of images in such a way that they are visible from both sides of the carrier, which carrier can be advanced by means of an advancing member that is connected movably to the casing and that is operated manually.
In a known embodiment of such a viewer, the carrier is round and supports a number of separate images, all of which are located at the same distance from the center of the carrier, in such a way that, when the carrier is rotated intermittently in the casing, these images can be viewed successively through the viewing aperture.
This known viewer entails several disadvantages. First of all, the carriers are relatively expensive, which is all the more objectionable since it is necessary to purchase an appreciable number of carriers with one casing if the viewer is to be used efficiently. Furthermore, the casing of the known apparatus is quite bulky.